Content localization in a network device

ABSTRACT

A media server comprises a network interface and an access controller. The network interface includes a cable testing module that performs a physical measurement of a first length of a first cable attached to the network interface. The access controller selectively grants a media request made by a first media client via the first cable if a first distance based upon the first length is less than a threshold.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/791,582, filed on Apr. 12, 2006. The disclosure of the aboveapplication is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to content localization in a networkdevice, and more specifically to limiting access based upon distance.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

Many audio and video applications are made digitally available to endusers by a service provider. When a service provider provides mediacontent to an end user, the service provider would like to ensure thatthe media content is consumed only by that end user and not by others,such as neighbors. Limiting media content to a given premises issometimes referred to as localization.

Referring now to FIG. 1, a functional block diagram of a medialocalization system according to the prior art is presented. A mediaserver 102 receives content from a service provider (not shown) andcommunicates with networking devices 104. A media client 106communicates with the networking devices 104. In order for the mediaserver 102 to determine whether to allow the media client 106 to accessmedia content, the media server 102 sends a delay request frame, such asa ping message, to the networking devices 104.

Each of the networking devices 104 forwards the delay request frame to asubsequent one of the networking devices 104 until the delay requestframe is sent to the media client 106. The media client 106 respondswith a delay response frame, which is forwarded through the networkingdevices 104 to the media server 102.

The media server 102 can then estimate the physical distance between themedia server 102 and the media client 106 by analyzing the time delaybetween the delay request frame and the delay response frame. This timedelay must be adjusted by removing the typical delay experienced by theframes within each of the networking devices 104. Adjustment isproblematic, however, because delays may vary greatly depending upon thecurrent state of the network.

Referring now to FIG. 2, a functional block diagram of a simple computernetwork is depicted. The network includes first and second PCs 150 and152, each containing a network interface, 154 and 156, respectively. Thenetwork interfaces 154 and 156 communicate with a networking device,such as a switch 158. The network interfaces 154 and 156 may includecable testing technology, such as Virtual Cable Tester™ from Marvell.Using cable testing, the network interfaces 154 and 156 can determinewhether there are any wiring faults between them and the switch 158.

SUMMARY

A media server comprises a network interface and an access controller.The network interface includes a cable testing module that performs aphysical measurement of a first length of a first cable attached to thenetwork interface. The access controller selectively grants a mediarequest made by a first media client via the first cable if a firstdistance based upon the first length is less than a threshold.

In other features, the first distance is equal to the first length whenthe first media client is attached to the first cable. The physicalmeasurement comprises a Time Domain Reflectometry (TDR) measurement. Thephysical measurement comprises transmitting a media access control (MAC)frame down the first cable and waiting for a corresponding signal to bereceived. The physical measurement comprises transmitting a physicallayer (PHY) frame down the first cable and waiting for a correspondingsignal to be received.

In further features, the access controller includes a distance tablethat includes respective distances from the media server to a pluralityof media clients including the first media client. The distance tablecontains validity information and a MAC address for each of therespective distances. The network interface includes a length table thatincludes lengths of cables that are attached to the network interface,the lengths including the first length of the first cable. An entry inthe length table is removed after a corresponding one of the cables isdisconnected.

In still other features, the network interface receives a length valuefrom a networking device interposed between the network interface andthe first media client. The length value is based upon a second lengthof a second cable attached between the networking device and the firstmedia client. The first distance is based upon the first length and thesecond length. The network interface transmits a cable length requestframe including a cumulative length value to the networking device andreceives a cable length response frame including the length value fromthe networking device. The length value is based upon the cumulativelength value and the second length. The cumulative length value is equalto the first length.

In other features, the access controller authenticates the first mediaclient before granting the media request. A content localization systemcomprises the media server of claim 1; the first media client; and anetworking device that communicates with the first media client and withthe media server, that includes a cable testing module that performs aphysical measurement of a second length of a second cable attachedbetween the networking device and the first media client, and thattransmits a message based upon the second length to the networkinterface.

A method comprises performing a physical measurement of a first lengthof a first cable; comparing a first distance based upon the first lengthto a threshold; and selectively granting a media request made by a firstmedia client via the first cable based upon the comparing.

In other features, the first distance is equal to the first length whenthe first media client is attached to the first cable. The methodfurther comprises performing a Time Domain Reflectometry (TDR)measurement. The method further comprises transmitting a media accesscontrol (MAC) frame down the first cable and waiting for a correspondingsignal to be received. The method further comprises transmitting aphysical layer (PHY) frame down the first cable and waiting for acorresponding signal to be received. The method further comprisesstoring a distance table that includes respective distances to aplurality of media clients including the first media client.

In further features, the distance table contains validity informationand a MAC address for each of the respective distances. The methodfurther comprises storing a length table that includes lengths ofattached cables, the lengths including the first length of the firstcable. The method further comprises removing an entry in the lengthtable after a corresponding one of the cables is disconnected. Themethod further comprises receiving a length value based upon a secondlength of a second cable attached en route to the first media client.The first distance is based upon the first length and the second length.

In still other features, the method further comprises transmitting acable length request frame including a cumulative length value andreceiving a cable length response frame including the length value. Thelength value is based upon the cumulative length value and the secondlength. The cumulative length value is equal to the first length. Themethod further comprises authenticating the first media client beforegranting the media request.

A media server comprises network interfacing means for providing networkaccess and for performing a physical measurement of a first length of afirst cable attached to the network interfacing means; and accesscontrol means for selectively granting a media request made by a firstmedia client via the first cable if a first distance based upon thefirst length is less than a threshold.

In other features, the first distance is equal to the first length whenthe first media client is attached to the first cable. The physicalmeasurement comprises a Time Domain Reflectometry (TDR) measurement. Thephysical measurement comprises transmitting a media access control (MAC)frame down the first cable and waiting for a corresponding signal to bereceived. The physical measurement comprises transmitting a physicallayer (PHY) frame down the first cable and waiting for a correspondingsignal to be received.

In further features, the access control means includes distance look-upmeans for storing respective distances from the media server to aplurality of media clients including the first media client. Thedistance look-up means contains validity information and a MAC addressfor each of the respective distances. The network interfacing meansincludes length look-up means for storing lengths of cables that areattached to the network interfacing means, the lengths including thefirst length of the first cable. An entry in the length look-up means isremoved after a corresponding one of the cables is disconnected.

In still other features, the network interfacing means receives a lengthvalue from a networking device interposed between the networkinterfacing means and the first media client. The length value is basedupon a second length of a second cable attached between the networkingdevice and the first media client. The first distance is based upon thefirst length and the second length. The network interfacing meanstransmits a cable length request frame including a cumulative lengthvalue to the networking device and receives a cable length responseframe including the length value from the networking device. The lengthvalue is based upon the cumulative length value and the second length.The cumulative length value is equal to the first length.

In other features, the access control means authenticates the firstmedia client before granting the media request. A content localizationsystem comprises the media server of claim 1; the first media client;and a networking device that communicates with the first media clientand with the media server, that includes cable testing means forperforming a physical measurement of a second length of a second cableattached between the networking device and the first media client, andthat transmits a message based upon the second length to the networkinterfacing means.

A computer program stored for use by a processor for operating a mediaserver comprises performing a physical measurement of a first length ofa first cable; comparing a first distance based upon the first length toa threshold; and selectively granting a media request made by a firstmedia client via the first cable based upon the comparing.

In other features, the first distance is equal to the first length whenthe first media client is attached to the first cable. The computerprogram further comprises performing a Time Domain Reflectometry (TDR)measurement. The computer program further comprises transmitting a mediaaccess control (MAC) frame down the first cable and waiting for acorresponding signal to be received. The computer program furthercomprises transmitting a physical layer (PHY) frame down the first cableand waiting for a corresponding signal to be received.

In further features, the computer program further comprises storing adistance table that includes respective distances to a plurality ofmedia clients including the first media client. The distance tablecontains validity information and a MAC address for each of therespective distances. The computer program further comprises storing alength table that includes lengths of attached cables, the lengthsincluding the first length of the first cable. The computer programfurther comprises removing an entry in the length table after acorresponding one of the cables is disconnected.

In still other features, the computer program further comprisesreceiving a length value based upon a second length of a second cableattached en route to the first media client. The first distance is basedupon the first length and the second length. The computer programfurther comprises transmitting a cable length request frame including acumulative length value and receiving a cable length response frameincluding the length value. The length value is based upon thecumulative length value and the second length. The cumulative lengthvalue is equal to the first length. The computer program furthercomprises authenticating the first media client before granting themedia request.

In other features, the systems and methods described above areimplemented by a computer program executed by one or more processors.The computer program can reside on a computer readable medium such asbut not limited to memory, non-volatile data storage and/or othersuitable tangible storage mediums.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the disclosure, are intended forpurposes of illustration only and are not intended to limit the scope ofthe disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of media localization according tothe prior art;

FIG. 2 is a functional block diagram of a simple computer network;

FIG. 3 is a functional block diagram of an exemplary contentlocalization system;

FIG. 4 is a functional block diagram depicting an exemplary homenetwork;

FIG. 5 is a flow chart depicting exemplary steps performed indetermining whether to grant or deny a media request from a mediaclient;

FIG. 6 is a graphical representation of exemplary tables storingattached cable lengths;

FIG. 7 is a graphical representation of an exemplary distance tablecontaining distances to media clients;

FIG. 8 is a flow chart depicting exemplary steps performed in measuringmedia client distance;

FIG. 9 is a flow chart depicting exemplary operation of a media serverusing a distance table;

FIG. 10A is a functional block diagram of a high definition television;

FIG. 10B is a functional block diagram of a set top box; and

FIG. 10C is a functional block diagram of a media player.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the disclosure, its application, or uses. For purposesof clarity, the same reference numbers will be used in the drawings toidentify similar elements. As used herein, the phrase at least one of A,B, and C should be construed to mean a logical (A or B or C), using anon-exclusive logical or. It should be understood that steps within amethod may be executed in different order without altering theprinciples of the present disclosure.

As used herein, the term module refers to an Application SpecificIntegrated Circuit (ASIC), an electronic circuit, a processor (shared,dedicated, or group) and memory that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablecomponents that provide the described functionality.

Referring now to FIG. 3, a functional block diagram of an exemplarycontent localization system according to the principles of the presentdisclosure is presented. A media server 200 includes an accesscontroller 201 and a media server network interface 202. The mediaserver network interface 202 further includes a cable testing module204. A router 210 includes first and second network interfaces 212 and214, each including a cable testing module, 216 and 218, respectively. Amedia client 220 includes a media client network interface 222. Themedia client network interface 222 may include a cable testing module224.

The first network interface 212 communicates with the media servernetwork interface 202. The second network interface 214 communicateswith the media client network interface 222. Cable testing technologycan be used to accurately measure the lengths of each network cablebetween the media server 200 and the media client 220. The accesscontroller 201 can use these lengths to estimate the physical distancebetween the media server 200 and the media client 220.

For example, the access controller 201 instructs the cable testingmodule 204 of the media server network interface 202 to measure thelength of the network cable between the media server 200 and the router210. This may be accomplished using Time Domain Reflectometry (TDR). Forexample, TDR is implemented by Marvell Virtual Cable Tester™. In TDR, apulse is sent down a cable and distance is determined based upon thelength of time before a reflected pulse is received. Using TDR mayrequire that the device at the other end of the cable present an open ora short termination to ensure a strong reflection.

Physical length measurement may also be accomplished by sending acontrol signal from the media server network interface 202 to the firstnetwork interface 212. Upon receiving such control signal, the firstnetwork interface 212 will respond with a corresponding signal. Thecontrol signal may include a control frame, such as a physical layer(PHY) frame or a media access control (MAC) frame.

The first network interface 212 can respond to such a control signalwithout involving higher protocol layers, such as the network ortransport layers, where delays vary based upon, for example, trafficvolume. Delays in lower protocol layers may be quantified andprogrammatically removed to accurately determine cable length.

After determining the length of the cable between the media server 200and the router 210, the access controller 201 instructs the media servernetwork interface 202 to send a cable length request frame to the firstnetwork interface 212. The determined cable length is included in thecable length request frame. The cable length request frame is thenforwarded to the second network interface 214. The cable testing module218 of the second network interface 214 then measures the length of thenetwork cable between the router 210 and the media client 220.

The measured length is added to the determined cable length contained inthe received cable length request frame, and a cable length responseframe is sent via the network interface 212 to the access controller201. The access controller 201 now knows the physical cable lengthbetween the media client 220 and the media server 200. If the mediaclient 220 is too far away, this may indicate that the media client 220is actually within a neighbor's premises. The access controller 201 maythen deny media requests from the media client 220.

Referring now to FIG. 4, a functional block diagram depicting anexemplary home network is presented. A broadband interface 250 receivescontent from a service provider (not shown). The broadband interface 250may include, for example, coaxial cable, satellite, and/or digitalsubscriber line (DSL). A media server, such as a set top box 252,communicates with the broadband interface 250. In some implementations,the set top box 252 implements the broadband interface 250. A first PC254 may communicate with the set top box 252.

A networking device, such as a router 256, communicates with the set topbox 252. The router 256 also communicates with a number of components,such as a digital TV 258, a media player 260, a second PC 262, and a DVDrecorder 264. Using the principles of the present disclosure, the settop box 252 can determine the cable length to any of the components 254,258, 260, 260, 262, and 264 to decide whether to grant or deny any mediarequests. The set top box 252 may, in addition to using physical layercable length measurements, employ higher layer authentication and/orauthorization protocols.

Referring now to FIG. 5, a flow chart depicts exemplary steps performedin deciding whether to grant or deny a media request. Control begins instep 300, where control waits for a media request. Once a media requestis received, control continues in step 302. In step 302, the set top boxmeasures the length of the first cable leading to the device making themedia request, and control continues in step 304.

Alternatively, control may proceed from step 300 to step 306. In step306, the length of the cable is read from a length table, and controlcontinues with step 304. The length table may be updated each time acable is connected to the set top box. The length table may be refreshedperiodically, and entries may be removed when cables are disconnected.The length table may not be refreshed frequently as cable length changesare very unlikely to occur without the cable being disconnected.

In step 304, control determines whether the media client making themedia request is directly attached to the set top box. If so, the totallength of cable is now known, and control transfers to step 308. If themedia client is not directly attached, further length measurements willbe performed, so control transfers to step 310. In step 310, a cablelength request frame containing the cumulative length of cableencountered thus far is forwarded to the next networking device in thepath to the media client. Control continues in step 312, where thelength of the next attached cable in the path to the media client ismeasured, and control continues in step 314.

Alternatively, control may proceed from step 310 to step 316, where apreviously measured length of the attached cable is read from a lengthtable, and control continues in step 314. As with the length tableassociated with the set top box, the length table associated with thenetworking device may be populated when new cables are connected.

In step 314, the measured length is added to the cumulative lengthreceived in the cable length request frame, and control continues instep 318. In step 318, if there are further networking devices betweenthe present networking device and the media client, control returns tostep 310; otherwise, control transfers to step 320. In step 320, thetotal cable length is now known and is sent in a cable length responseframe to the media server. Control continues in step 308, where themedia server compares the total cable length received in the cablelength response frame to a threshold value.

If the total cable length is greater than the threshold value, controltransfers to step 322; otherwise, control transfers to step 324. Thethreshold value may be determined when the service provider configuresservice for a customer. The threshold may differ based upon the type ofmedia client attached or may be specified for each specific mediaclient. In step 324, an authentication operation is performed.

If the authentication is successful, control transfers to step 326;otherwise, control transfers to step 322. In step 322, the media requestis denied and control ends. After one or more denied media requests, theset top box may forward information about denied media requests to theservice provider to assist in detecting attempted theft of service. Instep 326, the media request is granted and control ends.

Referring now to FIG. 6, exemplary tables 340 and 342 storing attachedcable lengths are depicted. The tables 340 and 342 may be used in steps306 and 316 of FIG. 5. The table 340 includes an entry for each portnumber of the device—eight in this example. The table 340 includes avalid field and a length field. The valid field may be set when a lengthreading has been made and cleared when the attached cable isdisconnected. The length field stores the length of the cable attachedto the corresponding port.

Table 342 represents an alternative storage scheme. The table 342contains as many entries as there are attached cables. The port numberof the attached cable is stored along with the length of thecorresponding cable. When the cable is disconnected, the entry isremoved from the table 342.

Referring now to FIG. 7, an exemplary distance table 350 containingdistances to media clients is depicted. The distance table 350 includesan entry for each media client that has made a request of the mediaserver. The distance table 350 may also be populated with media clientsattached to the network prior to the media clients making a request ofthe media server. The distance table 350 may include a valid field,which indicates whether the entry is valid, or alternatively, for howmuch longer the entry will be valid.

The distance table 350 includes a client number that uniquely identifiesthe media client. The client number may include, for example, a MACaddress. The distance table 350 includes a distance measurement from themedia server to the media client. The distance table 350 may alsoinclude a threshold value to which the distance is compared. Thethreshold may be specified separately for each media client, specifiedfor each type of media client, specified for all media clients, etc.

Referring now to FIG. 8, a flow chart depicts exemplary steps performedin measuring media client distance. Control begins in step 400, wherethe length of the cable attached to the set top box is measured. Controlcontinues in step 402, where if the media client is directly attached tothe set top box, control transfers to step 404; otherwise, controltransfers to step 406. In step 406, a cable length request framecontaining total cable length is forwarded to the next networking deviceand control continues in step 408.

In step 408, the length of the attached cable leading toward the mediaclient is measured. Control continues in step 410, where the measuredlength is added to the length contained within the received cable lengthrequest frame. Control continues in step 412, where if there are furthernetworking devices, control returns to step 406; otherwise, controltransfers to step 414. In step 414, a cable length response framecontaining the total cable length leading to the media client is sent tothe media server. Control continues in step 404, where the measureddistance to the media client is stored in a distance table, such as thedistance table 350 of FIG. 7. Control then ends.

Referring now to FIG. 9, a flow chart depicts exemplary operation of amedia server using a distance table, such as the distance table 350 ofFIG. 7. Control begins in step 450, where if a new media client has beenconnected, the distance to the new media client is determined accordingto FIG. 8, and control then resumes in step 452; otherwise, controltransfers directly to step 452. In step 452, if there is a media requestfrom a media client, control transfers to step 454; otherwise, controltransfers to step 456.

In step 454, distance and threshold values are read from the table forthe requesting media client. Control continues in step 458, where if thedistance is less than the threshold value, control transfers to step450; otherwise, control transfers to step 462. In step 460, the mediarequest is granted and control continues in step 456. In step 462, themedia request is denied and control continues in step 456.

In step 456, if a timer has expired, control transfers to step 463;otherwise, control returns to step 450. In step 463, the timer is resetand control continues in step 464. The timer duration is long enough tominimize network bandwidth used in updating lengths while stilldetecting changes in distance before much media content can be accessed.

In step 464, a pointer is set to point to the first table entry. Controlthen determines the distance to the media client of the table entryindicated by the pointer according to FIG. 8, and control resumes instep 466. In step 466, if there are further table entries, controltransfers to step 468; otherwise, control returns to step 450. In step468, the pointer is incremented to the next table entry. Control thendetermines the distance to the media client corresponding to the tableentry indicated by the pointer, according to FIG. 8, and control resumesin step 466.

Referring now to FIGS. 10A-10C, various exemplary implementationsincorporating the teachings of the present disclosure are shown.Referring now to FIG. 10A, the teachings of the disclosure can beimplemented in an external interface 545 of a high definition television(HDTV) 537. The HDTV 537 includes an HDTV control module 538, a display539, a power supply 540, memory 541, a storage device 542, a WLANinterface 543 and associated antenna 544, and the external interface545.

The HDTV 537 can receive input signals from the WLAN interface 543and/or the external interface 545, which sends and receives informationreceived via cable, broadband Internet, and/or satellite. The HDTVcontrol module 538 may process the input signals, including encoding,decoding, filtering, and/or formatting, and generate output signals. Theoutput signals may be communicated to one or more of the display 539,memory 541, the storage device 542, the WLAN interface 543, and theexternal interface 545.

Memory 541 may include random access memory (RAM) and/or nonvolatilememory such as flash memory, phase change memory, or multi-state memory,in which each memory cell has more than two states. The storage device542 may include an optical storage drive, such as a DVD drive, and/or ahard disk drive (HDD). The HDTV control module 538 communicatesexternally via the WLAN interface 543 and/or the external interface 545.The power supply 540 provides power to the components of the HDTV 537.

Referring now to FIG. 10B, the teachings of the disclosure can beimplemented in an external interface 587 of a set top box 578. The settop box 578 includes a set top control module 580, a display 581, apower supply 582, memory 583, a storage device 584, and a WLAN interface585 and associated antenna 586.

The set top control module 580 may receive input signals from the WLANinterface 585 and the external interface 587, which can send and receiveinformation received via cable, broadband Internet, and/or satellite.The set top control module 580 may process signals, including encoding,decoding, filtering, and/or formatting, and generate output signals. Theoutput signals may include audio and/or video signals in standard and/orhigh definition formats. The output signals may be communicated to theWLAN interface 585 and/or to the display 581. The display 581 mayinclude a television, a projector, and/or a monitor.

The power supply 582 provides power to the components of the set top box578. Memory 583 may include random access memory (RAM) and/ornonvolatile memory such as flash memory, phase change memory, ormulti-state memory, in which each memory cell has more than two states.The storage device 584 may include an optical storage drive, such as aDVD drive, and/or a hard disk drive (HDD).

Referring now to FIG. 10C, the teachings of the disclosure can beimplemented in an external interface 599 of a media player 589. Themedia player 589 may include a media player control module 590, a powersupply 591, memory 592, a storage device 593, a WLAN interface 594 andassociated antenna 595, and the external interface 599.

The media player control module 590 may receive input signals from theWLAN interface 594 and/or the external interface 599. The externalinterface 599 may include USB, infrared, and/or Ethernet. The inputsignals may include compressed audio and/or video, and may be compliantwith the MP3 format. Additionally, the media player control module 590may receive input from a user input 596 such as a keypad, touchpad, orindividual buttons. The media player control module 590 may processinput signals, including encoding, decoding, filtering, and/orformatting, and generate output signals.

The media player control module 590 may output audio signals to an audiooutput 597 and video signals to a display 598. The audio output 597 mayinclude a speaker and/or an output jack. The display 598 may present agraphical user interface, which may include menus, icons, etc. The powersupply 591 provides power to the components of the media player 589.

Memory 592 may include random access memory (RAM) and/or nonvolatilememory such as flash memory, phase change memory, or multi-state memory,in which each memory cell has more than two states. The storage device593 may include an optical storage drive, such as a DVD drive, and/or ahard disk drive (HDD).

Those skilled in the art can now appreciate from the foregoingdescription that the broad teachings of the disclosure can beimplemented in a variety of forms. Therefore, while this disclosureincludes particular examples, the true scope of the disclosure shouldnot be so limited since other modifications will become apparent to theskilled practitioner upon a study of the drawings, the specification andthe following claims.

What is claimed is:
 1. A content localization system, comprising: anetworking device; and a media server comprising an access controllerconfigured to receive, via a plurality of cables arranged in series, arequest for media content from a first media client; and a networkinterface including a cable testing module, wherein the cable testingmodule is configured to determine a physical length of a first cable ofthe plurality of cables, the first cable is attached to the networkinterface, the networking device is interposed between the networkinterface and the first media client, the networking device isconfigured to determine a physical length of a second cable of theplurality of cables, the second cable is attached to the networkingdevice, the network interface is configured to transmit, to thenetworking device, a cable length request frame including the physicallength of the first cable, in response to the cable length requestframe, the networking device is configured to transmit, to the networkinterface, a cable length response frame including a length value, thelength value is based on a sum of (i) the physical length of the firstcable from the cable length request frame and (ii) the physical lengthof the second cable, the media server is configured to determine anoverall physical length of the plurality of cables in response to thelength value from the cable length response frame, and the accesscontroller is configured to deny the request for the media content madeby the first media client in response to the overall physical length ofthe plurality of cables being greater than a predetermined threshold,and store a distance table that includes the overall physical length ofthe plurality of cables.
 2. The content localization system of claim 1,wherein the cable testing module is configured to determine the physicallength of the first cable using Time Domain Reflectometry (TDR) andwherein the networking device is configured to determine the physicallength of the second cable using TDR.
 3. The content localization systemof claim 1, wherein the cable testing module is configured to determinethe physical length of the first cable by transmitting a media accesscontrol (MAC) frame and waiting for a corresponding response frame to bereceived.
 4. The content localization system of claim 1, wherein thecable testing module is configured to determine the physical length ofthe first cable by transmitting a physical layer (PHY) frame and waitingfor a corresponding response frame to be received.
 5. The contentlocalization system of claim 1, wherein the distance table includesvalidity information and a MAC address for each of a plurality of mediaclients in communication with the media server, the plurality of mediaclients including the first media client.
 6. The content localizationsystem of claim 5, wherein the network interface is configured to removean entry from the distance table in response to a corresponding one ofthe plurality of media clients being disconnected.
 7. The contentlocalization system of claim 1, wherein the access controller isconfigured to authenticate the first media client before granting therequest for the media content from the first media client.
 8. Thecontent localization system of claim 1, wherein the access controller isconfigured to store entries in the distance table correspondingrespectively to a plurality of media clients in communication with themedia server, the plurality of media clients including the first mediaclient, wherein each of the entries includes (i) an identifier of thecorresponding media client and (ii) an overall cable length between themedia server and the corresponding media client.
 9. The contentlocalization system of claim 8, wherein the access controller isconfigured to (i) store a configurable threshold for each of the entriesand (ii) deny a request for media content made by one of the pluralityof media clients in response to the overall cable length correspondingto the one of the plurality of media clients being greater than theconfigurable threshold corresponding to the one of the plurality ofmedia clients.
 10. The content localization system of claim 8, whereinthe access controller is configured to store a second table includingentries corresponding to a plurality of ports of the network interface,wherein each entry includes a physical cable length of a cable attachedto the corresponding port.
 11. A method of operating a media server, themethod comprising: receiving, via a plurality of cables arranged inseries, a request for media content from a first media client;determining a physical length of a first cable of the plurality ofcables, wherein the first cable is attached to the media server;transmitting a cable length request frame, including the physical lengthof the first cable, from the media server to a networking device,wherein the networking device is interposed between the media server andthe first media client; receiving, at the media server, a cable lengthresponse frame including a length value wherein the length value isbased on a sum of (i) the physical length of the first cable from thecable length request frame and (ii) a physical length of a second cableof the plurality of cables as measured by the networking device;determining an overall physical length of the plurality of cables inresponse to the length value from the cable length response frame;comparing the overall physical length of the plurality of cables to apredetermined threshold; selectively denying the request for the mediacontent made by the first media client in response to the comparing; andstoring a distance table including the overall physical length of theplurality of cables.
 12. The method of claim 11, further comprisingdetermining the physical length of the first cable using Time DomainReflectometry (TDR).
 13. The method of claim 11, further comprisingdetermining the physical length of the first cable by transmitting amedia access control (MAC) frame and waiting for a correspondingresponse frame to be received.
 14. The method of claim 11, furthercomprising determining the physical length of the first cable bytransmitting a physical layer (PHY) frame and waiting for acorresponding response frame to be received.
 15. The method of claim 11,further comprising storing, in the distance table, validity informationand a MAC address for each of a plurality of media clients incommunication with the media server, the plurality of media clientsincluding the first media client.
 16. The method of claim 15, furthercomprising removing an entry from the distance table in response to acorresponding one of the plurality of media clients being disconnected.17. The method of claim 11, further comprising authenticating the firstmedia client before granting the request for the media content from thefirst media client.
 18. The method of claim 11, further comprisingstoring entries in the distance table corresponding respectively to aplurality of media clients in communication with the media server, theplurality of media clients including the first media client, whereineach of the entries includes (i) an identifier of the correspondingmedia client and (ii) an overall cable length between the media serverand the corresponding media client.
 19. The method of claim 18, furthercomprising: storing a configurable threshold for each of the entries;and denying a request for media content made by one of the plurality ofmedia clients in response to the overall cable length corresponding tothe one of the plurality of media clients being greater than theconfigurable threshold corresponding to the one of the plurality ofmedia clients.
 20. The method of claim 18, further comprising storing asecond table including entries corresponding to a plurality of ports ofthe media server, wherein each entry includes a physical cable length ofa cable attached to the corresponding port.